[Qemu-devel] [PATCH] target-mips: fix semihosting for microMIPS R6

[Qemu-devel] [PATCH] target-mips: fix semihosting for microMIPS R6

[Leon Alrae]

In semihosting mode the SDBBP 1 instructions should trigger UHI syscall,
but in QEMU this does not happen for recently added microMIPS R6.
Consequently bare metal microMIPS R6 programs supporting UHI will not run.

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
---
 target-mips/translate.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/target-mips/translate.c b/target-mips/translate.c
index d1de35a..e299643 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -13278,10 +13278,14 @@ static void gen_pool16c_r6_insn(DisasContext *ctx)
             break;
         case R6_SDBBP16:
             /* SDBBP16 */
-            if (ctx->hflags & MIPS_HFLAG_SBRI) {
-                generate_exception(ctx, EXCP_RI);
+            if (is_uhi(extract32(ctx->opcode, 6, 4))) {
+                gen_helper_do_semihosting(cpu_env);
             } else {
-                generate_exception(ctx, EXCP_DBp);
+                if (ctx->hflags & MIPS_HFLAG_SBRI) {
+                    generate_exception(ctx, EXCP_RI);
+                } else {
+                    generate_exception(ctx, EXCP_DBp);
+                }
             }
             break;
         }
-- 
2.1.0

Re: [Qemu-devel] [PATCH] target-mips: fix semihosting for microMIPS R6

[Aurelien Jarno]

On 2015-08-03 13:01, Leon Alrae wrote:
> In semihosting mode the SDBBP 1 instructions should trigger UHI syscall,
> but in QEMU this does not happen for recently added microMIPS R6.
> Consequently bare metal microMIPS R6 programs supporting UHI will not run.
> 
> Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
> ---
>  target-mips/translate.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)

Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net